ArticleUnderstanding Bentonite, Refractometers vs. Hydrometers, and Mellowing A Big WineWritten by Alison CroweMost folks I talk to say that sodium bentonite and calcium bentonite are interchangeable in winemaking.Already a member? Log InYou'll Also Like Article MEMBERS ONLY Lysozyme, Adding Sugar, and Oak Alternatives Excluding bacteria that can eat malic acid and turn it into lactic acid is the only way to make sure you don’t get refermentation in the bottle. Article MEMBERS ONLY Perfecting Pyment, Vinifera Vines, and Over-Yeasting . . . you could also buy some powdered grape tannin, use oak chips, or even use a cup of strong black tea to add some tannin backbone to the wine if it’d be tough for you to obtain grape skins.